1. Technical Field
The present invention relates to a recording apparatus and a liquid ejecting apparatus and more particularly to a recording apparatus and a liquid ejecting apparatus using an ultraviolet curing ink.
2. Related Art
There is provided a recording apparatus or a liquid ejecting apparatus for forming an image or a pattern on a recording medium using an ultraviolet curing ink. The ultraviolet curing ink has preferred characteristics that the ultraviolet curing ink is slowly cured before ultraviolet rays are irradiated and is rapidly cured when the ultraviolet rays are irradiated, as a print ink. Since a solvent is not volatilized at the time of curing, an environment load is small.
The ultraviolet curing ink has excellent characteristics that an adhesion property is high with respect to various recoding mediums due to composition of vehicle, the ink becomes chemically stable after curing, an adhesion property, chemical resistance, weatherability, and friction resistance are high, and the ink is bearable in the outdoor environment. Accordingly, instead of a recording medium having a thin sheet shape, such as paper, a resin film or a metal foil, an image can be formed on a medium having a stereoscopic surface shape, such as a label surface of an optical recording medium or a textile product.
As a method of attaching the ultraviolet curing ink to a recording medium, a coating method or a printing method may be used, but an ink jet recording apparatus which can form any image or pattern with high precision without a printing plate may be used. By a combination of main scan for moving a recording head for ejecting an ink and sub scan for moving the recording medium in a direction crossing a main scan direction, an image can be recorded in any area with respect to a long or wide recording medium using a nozzle having a restricted dimension.
In JP-A-2004-155046, an ink jet recording apparatus for irradiating an ink including an ultraviolet curing agent onto a recording surface immediately after recording so as to improve a quick drying property of the recording surface is described. In more detail, in the ink jet printer, the ultraviolet curing ink is used as the ink and the ink attached to the recording medium is immediately cured and fixed by ultraviolet lamps provided at the both ends of the main scan direction of the recording head.
In JP-A-2005-324443 and JP-A-2005-125513, an image forming apparatus which includes recording heads for ejecting an ink cured by irradiating ultraviolet rays and an ultraviolet ray irradiation unit connected to the recording heads and relatively moves an image support, the recording head and the ultraviolet ray irradiation unit is described. In the image forming apparatus described herein, an input digital image is formed on the image support by scan of the plurality of recording heads and the ink is individually cured by irradiating the ultraviolet rays for each scan. In JP-A-2004-042548, ultraviolet rays are individually irradiated for each color in a recording apparatus for ejecting ultraviolet curing inks having different colors from nozzles so as to perform color printing.
However, when the image is formed using the ultraviolet curing ink, the image may be recorded on the recording medium having translucency, such as a resin film, using the high adhesion property. In this case, for the purpose of suppressing influence on the color tone of the image of the light passing through the medium, the image may be formed after an undercoat layer is formed by a coat ink having a high hiding property over an area in which the image is formed on the recording medium. The overcoat layer may be formed by covering the surface of the image formed on the recording medium with the transparent coat ink such that the image is protected and the surface of the area in which the image is formed smoothens.
With respect to the transparent recording medium, an image may be formed from a rear surface so as to be visible through the recording medium. In this case, for the purpose of maintaining the color tone of the image and cover the rear surface of the image, a back coat layer may be formed by covering the rear surface of the image formed on the recording medium with an ink having a higher hiding property.
The ink for coating may include a large amount of pigment for the purpose of increasing the hiding property or may not include the pigment in order to ensure transparency. That is, the ink for coating has properties different from those of many color inks in chemical properties or optical properties. Accordingly, in the case where the ink is coated by the ink jet method, the nozzle specification is different and the wavelength and the irradiation amount of the ultraviolet rays irradiated for curing is different. Accordingly, in the case of forming the image having the coat layer, the image is formed by two recording processes using the recording apparatus which individually includes a coat ink recording unit and an image recording unit.
However, in the above-described structure, the scale of the recording apparatus is increased and the throughput of a recording operation is increased. Since the printing sequences of the case of forming the undercoat layer and the case of forming the overcoat layer or the back coat layer are inverse, the operation of the recording apparatus is troublesome. Even when both the undercoat layer and the overcoat layer are formed, the operation sequence is further increased. Accordingly, the cost of a product including various types of coat layers is increased.